diff --git a/executor/aggregate.go b/executor/aggregate.go
index cf5bf5687e07f..145fd0f7ae2a1 100644
--- a/executor/aggregate.go
+++ b/executor/aggregate.go
@@ -571,11 +571,24 @@ func getGroupKey(ctx sessionctx.Context, input *chunk.Chunk, groupKey [][]byte,
 
 	for _, item := range groupByItems {
 		tp := item.GetType()
+
 		buf, err := expression.GetColumn(tp.EvalType(), numRows)
 		if err != nil {
 			return nil, err
 		}
 
+		// In strict sql mode like ‘STRICT_TRANS_TABLES’，can not insert an invalid enum value like 0.
+		// While in sql mode like '', can insert an invalid enum value like 0,
+		// then the enum value 0 will have the enum name '', which maybe conflict with user defined enum ''.
+		// Ref to issue #26885.
+		// This check is used to handle invalid enum name same with user defined enum name.
+		// Use enum value as groupKey instead of enum name.
+		if item.GetType().GetType() == mysql.TypeEnum {
+			newTp := *tp
+			newTp.AddFlag(mysql.EnumSetAsIntFlag)
+			tp = &newTp
+		}
+
 		if err := expression.EvalExpr(ctx, item, tp.EvalType(), input, buf); err != nil {
 			expression.PutColumn(buf)
 			return nil, err
@@ -586,6 +599,7 @@ func getGroupKey(ctx sessionctx.Context, input *chunk.Chunk, groupKey [][]byte,
 			newTp.Flen = 0
 			tp = &newTp
 		}
+
 		groupKey, err = codec.HashGroupKey(ctx.GetSessionVars().StmtCtx, input.NumRows(), buf, groupKey, tp)
 		if err != nil {
 			expression.PutColumn(buf)
diff --git a/executor/aggregate_test.go b/executor/aggregate_test.go
index 0effc00bd7613..b569526c533a5 100644
--- a/executor/aggregate_test.go
+++ b/executor/aggregate_test.go
@@ -1529,3 +1529,150 @@ func (s *testSerialSuite) TestAggInDisk(c *C) {
 	tk.MustQuery("select /*+ HASH_AGG() */ count(c) from t;").Check(testkit.Rows("0"))
 	tk.MustQuery("select /*+ HASH_AGG() */ count(c) from t group by c1;").Check(testkit.Rows())
 }
+<<<<<<< HEAD
+=======
+
+func TestRandomPanicAggConsume(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("set @@tidb_max_chunk_size=32")
+	tk.MustExec("set @@tidb_init_chunk_size=1")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int)")
+	for i := 0; i <= 1000; i++ {
+		tk.MustExec(fmt.Sprintf("insert into t values(%v),(%v),(%v)", i, i, i))
+	}
+
+	fpName := "github.com/pingcap/tidb/executor/ConsumeRandomPanic"
+	require.NoError(t, failpoint.Enable(fpName, "5%panic(\"ERROR 1105 (HY000): Out Of Memory Quota![conn_id=1]\")"))
+	defer func() {
+		require.NoError(t, failpoint.Disable(fpName))
+	}()
+
+	// Test 10 times panic for each AggExec.
+	var res sqlexec.RecordSet
+	for i := 1; i <= 10; i++ {
+		var err error
+		for err == nil {
+			// Test paralleled hash agg.
+			res, err = tk.Exec("select /*+ HASH_AGG() */ count(a) from t group by a")
+			if err == nil {
+				_, err = session.GetRows4Test(context.Background(), tk.Session(), res)
+				require.NoError(t, res.Close())
+			}
+		}
+		require.EqualError(t, err, "failpoint panic: ERROR 1105 (HY000): Out Of Memory Quota![conn_id=1]")
+
+		err = nil
+		for err == nil {
+			// Test unparalleled hash agg.
+			res, err = tk.Exec("select /*+ HASH_AGG() */ count(distinct a) from t")
+			if err == nil {
+				_, err = session.GetRows4Test(context.Background(), tk.Session(), res)
+				require.NoError(t, res.Close())
+			}
+		}
+		require.EqualError(t, err, "failpoint panic: ERROR 1105 (HY000): Out Of Memory Quota![conn_id=1]")
+
+		err = nil
+		for err == nil {
+			// Test stream agg.
+			res, err = tk.Exec("select /*+ STREAM_AGG() */ count(a) from t")
+			if err == nil {
+				_, err = session.GetRows4Test(context.Background(), tk.Session(), res)
+				require.NoError(t, res.Close())
+			}
+		}
+		require.EqualError(t, err, "failpoint panic: ERROR 1105 (HY000): Out Of Memory Quota![conn_id=1]")
+	}
+}
+
+func TestIssue35295(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t100")
+	// This bug only happens on partition prune mode = 'static'
+	tk.MustExec("set @@tidb_partition_prune_mode = 'static'")
+	tk.MustExec(`CREATE TABLE t100 (
+ID bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+col1 int(10) NOT NULL DEFAULT '0' COMMENT 'test',
+money bigint(20) NOT NULL COMMENT 'test',
+logtime datetime NOT NULL COMMENT '记录时间',
+PRIMARY KEY (ID,logtime)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin AUTO_INCREMENT=1 COMMENT='test'
+PARTITION BY RANGE COLUMNS(logtime) (
+PARTITION p20220608 VALUES LESS THAN ("20220609"),
+PARTITION p20220609 VALUES LESS THAN ("20220610"),
+PARTITION p20220610 VALUES LESS THAN ("20220611"),
+PARTITION p20220611 VALUES LESS THAN ("20220612"),
+PARTITION p20220612 VALUES LESS THAN ("20220613"),
+PARTITION p20220613 VALUES LESS THAN ("20220614"),
+PARTITION p20220614 VALUES LESS THAN ("20220615"),
+PARTITION p20220615 VALUES LESS THAN ("20220616"),
+PARTITION p20220616 VALUES LESS THAN ("20220617"),
+PARTITION p20220617 VALUES LESS THAN ("20220618"),
+PARTITION p20220618 VALUES LESS THAN ("20220619"),
+PARTITION p20220619 VALUES LESS THAN ("20220620"),
+PARTITION p20220620 VALUES LESS THAN ("20220621"),
+PARTITION p20220621 VALUES LESS THAN ("20220622"),
+PARTITION p20220622 VALUES LESS THAN ("20220623"),
+PARTITION p20220623 VALUES LESS THAN ("20220624"),
+PARTITION p20220624 VALUES LESS THAN ("20220625")
+ );`)
+	tk.MustExec("insert into t100(col1,money,logtime) values (100,10,'2022-06-09 00:00:00');")
+	tk.MustExec("insert into t100(col1,money,logtime) values (100,10,'2022-06-10 00:00:00');")
+	tk.MustQuery("SELECT /*+STREAM_AGG()*/ col1,sum(money) FROM t100 WHERE logtime>='2022-06-09 00:00:00' AND col1=100 ;").Check(testkit.Rows("100 20"))
+	tk.MustQuery("SELECT /*+HASH_AGG()*/ col1,sum(money) FROM t100 WHERE logtime>='2022-06-09 00:00:00' AND col1=100 ;").Check(testkit.Rows("100 20"))
+}
+
+// https://github.com/pingcap/tidb/issues/27751
+func TestIssue27751(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table test.t(nname char(20));")
+	tk.MustExec("insert into test.t values ('2'),(null),('11'),('2'),(null),('2'),(null),('11'),('33');")
+	tk.MustExec("set @@group_concat_max_len=0;")
+	tk.MustQuery("select group_concat(nname order by 1 separator '#' ) from t;").Check(testkit.Rows("11#1"))
+	tk.MustQuery("select group_concat(nname order by 1 desc separator '#' ) from t;").Check(testkit.Rows("33#2"))
+}
+
+func TestIssue26885(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`SET sql_mode = 'NO_ENGINE_SUBSTITUTION';`)
+	tk.MustExec(`DROP TABLE IF EXISTS t1;`)
+
+	tk.MustExec("CREATE TABLE t1 (c1 ENUM('a', '', 'b'));")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('b');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('a');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES (0);")
+	tk.MustQuery("select * from t1").Check(testkit.Rows("b", "", "a", "", ""))
+	tk.MustQuery("select c1 + 0 from t1").Check(testkit.Rows("3", "2", "1", "2", "0"))
+	tk.MustQuery("SELECT c1 + 0, COUNT(c1) FROM t1 GROUP BY c1 order by c1;").Check(testkit.Rows("0 1", "1 1", "2 2", "3 1"))
+
+	tk.MustExec("alter table t1 add index idx(c1); ")
+	tk.MustQuery("select c1 + 0 from t1").Check(testkit.Rows("3", "2", "1", "2", "0"))
+	tk.MustQuery("SELECT c1 + 0, COUNT(c1) FROM t1 GROUP BY c1 order by c1;").Check(testkit.Rows("0 1", "1 1", "2 2", "3 1"))
+
+	tk.MustExec(`DROP TABLE IF EXISTS t1;`)
+	tk.MustExec("CREATE TABLE t1 (c1 ENUM('a', 'b', 'c'));")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('b');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('a');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('b');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES ('c');")
+	tk.MustExec("INSERT INTO t1 (c1) VALUES (0);")
+	tk.MustQuery("select * from t1").Check(testkit.Rows("b", "a", "b", "c", ""))
+	tk.MustQuery("SELECT c1 + 0, COUNT(c1) FROM t1 GROUP BY c1 order by c1;").Check(testkit.Rows("0 1", "1 1", "2 2", "3 1"))
+}
+>>>>>>> 065563a8e... executor: fix aggregating enum zero value gets different results from mysql  (#36208)